I wish we had higher resolution pix of this one. While, as noted, this could be FG-1D 87933 or F4U-1D 57933, I suspect it is the former. Without reading the tail markings, it's a guess at best. Both aircraft would have had the combat prop, both would have had the armored glass doubling as a gunsight reflector, and both would have had the frameless canopy. Only the FG-1D would have come with the step in the inboard right-side flap - while I can see the step door clearly, I think it's there. Neither aircraft would have left the factory with the carbon monoxide scoops on the aft fuselage, but both should have had the scoops added in service. Neither aircraft would have moved the MHF wire connection from the right side of the fuselage to the left, and both could have made the switch in the field - but that change was
very common on FG-1Ds, and I've never seen it on an identifiable F4U-1D.
The nose numbers (last three of the BuNo from the factory) were applied with a temporary, gasoline-based paint, and were meant to be washed off on delivery. Some units never washed them off, others washed them off and replaced them with new numbers based on a unit coding system.
If you are interested in additional details, I've popped out a couple of books on the Dash-1 family of Corsairs:
http://www.amazon.com/Aircraft-Pictoria ... 160%2C160_http://www.amazon.com/Aircraft-Pictoria ... 160%2C160_Cheers,
Dana